<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<title>title</title>
	</head>
	<body>
		<div id="father">
			<div>11</div>
			<div>22
				<p>111</p>
				<p>222</p>
				<p>333</p>
			</div>
			<div>33</div>
			<div>44</div>
			<div>55</div>
			<p>66</p>
			<p>77</p>
			<p>88</p>
		</div>
		<script src="jquery-1.12.4.js" type="text/javascript" charset="utf-8"></script>
		<script type="text/javascript">
			$(function(){
				$("s1,s2")//	并集选择器
				$("s1 s2")//    后代选择器
				$("s1>s2")//    子代选择器
				
				$("li.green")
				$("s1s2")//交集选择器
				
				// $("#father>p").css("backgroundColor","red");
				$("#father p").css("backgroundColor","red");
			});
		</script>
	</body>
</html>